559 research outputs found
Solution of Nonlinear Elliptic Boundary Value Problems and Its Iterative Construction
We study a kind of nonlinear elliptic boundary value problems with generalized
p-Laplacian operator. The unique solution is proved to be existing and the relationship between this
solution and the zero point of a suitably defined nonlinear maximal monotone operator is investigated.
Moreover, an iterative scheme is constructed to be strongly convergent to the unique solution. The
work done in this paper is meaningful since it combines the knowledge of ranges for nonlinear operators,
zero point of nonlinear operators, iterative schemes, and boundary value problems together. Some new
techniques of constructing appropriate operators and decomposing the equations are employed, which
extend and complement some of the previous work
Quantum phases of SrCu2(BO3)2 from high-pressure thermodynamics
We report heat capacity measurements of SrCu(BO) under high
pressure along with simulations of relevant quantum spin models and map out the
phase diagram of the material. We find a first-order quantum phase
transition between the low-pressure quantum dimer paramagnet and a phase with
signatures of a plaquette-singlet state below T = K. At higher pressures,
we observe a transition into a previously unknown antiferromagnetic state below
K. Our findings can be explained within the two-dimensional
Shastry-Sutherland quantum spin model supplemented by weak inter-layer
couplings. The possibility to tune SrCu(BO) between the
plaquette-singlet and antiferromagnetic states opens opportunities for
experimental tests of quantum field theories and lattice models involving
fractionalized excitations, emergent symmetries, and gauge fluctuations.Comment: 6 pages + 8 pages supplemental informatio
The vital role of hole-carriers for superconductivity in pressurized black phosphorus
The influence of carrier type on superconductivity has been an important
issue for understanding both conventional and unconventional superconductors
[1-7]. For elements that superconduct, it is known that hole-carriers govern
the superconductivity for transition and main group metals [8-10]. The role of
hole-carriers in elements that are not normally conducting but can be converted
to superconductors, however, remains unclear due to the lack of experimental
data. Here we report the first in-situ high pressure Hall effect measurements
on single crystal black phosphorus, measured up to ~ 50 GPa, and find a
correlation between the Hall coefficient and the superconducting transition
temperature (TC). Our results reveal that hole-carriers play a vital role in
developing superconductivity and enhancing TC. Importantly, we also find a
Lifshitz transition in the high-pressure cubic phase at ~17.2GPa, which
uncovers the origin of a puzzling valley in the superconducting TC-pressure
phase diagram. These results offer insight into the role of hole-carriers in
developing superconductivity in simple semiconducting solids under pressure.Comment: 9 pages anf 3 figure
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